Selenium

Selenium is a metallic gray to black mineral element present in most rocks and soils. In nature it combines with sulfide or with silver, copper, lead, and nickel minerals. Selenium is found in coal waste and sewage sludge.

Uses
Selenium is used in the electronics, glass, and pharmaceutical industry. It is also used as a nutritional supplement, as a component of pigments in plastics, paints, enamels, inks, and rubber; as a feed additive for poultry and livestock; in pesticide formulations and as an ingredient in antidandruff shampoos; and as a component of fungicides. Additionally, radioactive selenium is used in diagnostic medicine. What happens to selenium when it enters the environment?

In the Environment
Selenium is naturally found in the environment and it can be released by both natural processes or human activity (like manufacturing). Selenium dust enters the air from burning coal and oil. This eventually settles over the land and water. Selenium also enters water from rocks and soil, and from agricultural and industrial waste. Whereas some selenium compounds can dissolve in water, others settle to the bottom in sediment. In soil, insoluble forms of selenium remains in the soil, but soluble forms may enter surface water from soil. Selenium may accumulate up the food chain.

In Sewage Sludge
In sewage sludge applied to land, the U.S. EPA limits selenium to a concentration of 100 parts per million. In the Targeted National Sewage Sludge Survey, a 2009 test of 84 samples of sewage sludge from around the U.S., the EPA found selenium in every sample in concentrations ranging from 1.10 to 24.7 parts per million.

Coal and Selenium
Burning coal produces airborne compounds, known as fly ash and bottom ash (collectively referred to as coal ash), which can contain large quantities of heavy metals like selenium that settle or wash out of the atmosphere into oceans, streams, and land. The 1.05 billion tons of coal burned each year in the United States contain 109 tons of mercury, 7884 tons of arsenic, 1167 tons of beryllium, 750 tons of cadmium, 8810 tons of chromium, 9339 tons of nickel, and 2587 tons of selenium. On top of emitting 1.9 billion tons of carbon dioxide each year, coal-fired power plants in the United States also create 120 million tons of toxic coal waste. That means each of the nation's 500 coal-fired power plants produces an average 240,000 tons of toxic waste each year. A power plant that operates for 40 years will leave behind 9.6 million tons of toxic waste. This coal combustion waste (CCW) constitutes the nation's second largest waste stream after municipal solid waste.

Rain falling on coal storage piles and ash piles can leach out these heavy metal compounds into ground water or lakes and streams, contaminating drinking water sources.

West Virginia hearings on Patriot Coal's selenium levels
In August 2010, the environmental groups Ohio Valley Environmental Coalition, the West Virginia Highlands Conservancy, and the Sierra Club are facing off against Patriot Coal in federal court over the company's selenium levels in West Virginia. Since 2003, federal and state regulators have tried to control selenium levels in rivers and streams. But coal companies have continuously asked for more time to come into compliance. In June 2010, U.S. District Judge Chuck Chambers ruled that Patriot’s Hobet 21 Surface Mine in Lincoln County, WV, was continuing to discharge selenium in illegally high amounts, and that the company hadn’t taken enough steps toward selenium compliance. The judge is expected to issue an order by the end of August, which will lay out what, if anything, Patriot has to do. Environmentalists are also asking Chambers to hold Patriot in contempt of court for not following previous court orders to come into compliance with selenium discharge. John McHale, from Patriot Coal, testified that the company will probably go ahead with a method called Fluidized Bed Reactor, or FBR.

On September 1, 2010, Patriot Coal was found in contempt of court by Judge Chambers and ordered to clean up selenium pollution at the two mines in West Virginia. Chambers ordered Patriot subsidiary Apogee Coal to install treatment systems and comply with discharge limits by March 1, 2013, and ordered Patriot subsidiary Hobet Mining to submit a selenium treatment plan by Oct. 1 and comply with pollution limits in its operating permit by May 1, 2013. The coal producer estimates the it will cost $50 million to comply with the judgment, plus $3 million in annual operating costs. Chambers also ordered Patriot to post a $45 million letter of credit to guarantee the treatment systems are installed.

Selenium discharges at West Virginia Mine
On March 23, 2011, three environmental groups sued coal operator ICG Eastern in federal court over the Knight-Ink Mine in West Virginia, saying the mine had been discharging toxic selenium into streams for years. The Sierra Club, the Ohio Valley Environmental Coalition and the West Virginia Highlands Conservancy filed the case in U.S. District Court in Elkins, alleging violations of state and federal law, including the federal Clean Water Act and the Surface Mining Control and Reclamation Act. The complaint also claims state regulators have been lax in cracking down on ICG, allowing discharges into Big Beaver Creek, and two tributaries, Oldhe Fork and Board Fork, at levels above those designed to protect aquatic life. The mine is in east-central West Virginia, near the Monongahela National Forest.

Human Exposure
Most people are exposed to very low levels of selenium in air, food, and water. People may be exposed to higher levels if they live or work near industries where selenium is produced, processed, or made into commercial products, or if they live near hazardous waste sites or coal burning plants.

Health Effects
Selenium is needed in low dose for good health, but exposure to high levels can cause adverse health effects. "Short-term oral exposure to high concentrations of selenium may cause nausea, vomiting, and diarrhea. Chronic oral exposure to high concentrations of selenium compounds can produce a disease called selenosis. The major signs of selenosis are hair loss, nail brittleness, and neurological abnormalities (such as numbness and other odd sensations in the extremities)."

"Brief exposures to high levels of elemental selenium or selenium dioxide in air can result in respiratory tract irritation, bronchitis, difficulty breathing, and stomach pains. Longer-term exposure to either of these air-borne forms can cause respiratory irritation, bronchial spasms, and coughing. Levels of these forms of selenium that would be necessary to produce such effects are normally not seen outside of the workplace."

"Animal studies have shown that very high amounts of selenium can affect sperm production and the female reproductive cycle. We do not know if similar effects would occur in humans."

Related SourceWatch articles

 * Biosolids
 * Sewage sludge
 * Food Rights Network
 * Heavy metals and coal

External resources

 * World Health Organization, Chemical hazards in drinking-water - selenium
 * ToxFAQs for Selenium, Agency for Toxic Substances & Disease Registry.
 * Dietary Supplement Fact Sheet: Selenium, National Institutes of Health